AUDIE CORNISH, HOST:
More now on that controversial interview Melissa mentioned with Newt Gingrich's former wife Marianne. She has told ABC News that the former speaker wanted an open marriage so he could have both a mistress and a wife. The interview is set to run on ABC's "Nightline" this evening. Excerpts were released this morning, just two days before the South Carolina primary.
NPR's Kathy Lohr has that story.
KATHY LOHR, BYLINE: In the interview, Marianne Gingrich says Newt admitted to an affair with a congressional staffer, Callista Bisek, for six years. She told ABC's Brian Ross that he wanted to continue this relationship with the woman who became his third wife.
(SOUNDBITE OF ABC'S "NIGHTLINE")